The Rubin (large synoptic survey, LSST) telescope, is one of the most challenging astronomical projects for the next decade. The telescope will be able to observe the entire southern skies every three nights, in multiple bands, and will do so for about 10 years. At completion, the sky map build by LSST will be the most accurate and deep map of more than half of the sky. The telescope, with a primary mirror of ~8.5m, equipped with a camera capable of observing a sky area of ~50 times the size of the moon in a single pointing, is being built on the Cerro Pachon, in the north of Chile.

Researchers of the INAF-OA Abruzzo are participating to several LSST projects.


Luminous and Dark Matter in galaxies: distances and scaling relations from the local Universe to z~1.5

This science project is leaded by Michele Cantiello, researcher at the OA Abruzzo. The program is dedicated to derive distances of galaxies out to 100 Mpc, and possibly more, with the surface brightness fluctuations method (SBF) by using the huge amount of data produced by LSST.

The SBF measurement with LSST data is by itself very challenging, as the measurement of the fluctuations in galaxies, to date, is carried out on single objects, with a very time consuming procedure. LSST will provide data for thousands, or possibly millions of galaxies where the SBF signal could be detected. Hence, a big effort is required to be able to processing such dataset with the least possible human intervention.

If successful, our SBF measurements to LSST data will generate the most accurate 3D map ever of the southern sky.


EM counterparts of gravitational wave sources.

Thanks to the extended field of view (9.6 square degrees), a recurrent mapping of the sky down to low luminosity, and the capability of detecting very weak sources with precision (band magnitude r> 24.5mag), the Rubin Telescope is an ideal telescope for the search of the electromagnetic (EM) counterparts of gravitational wave (GW) events. Furthermore, the production of catalogs with data from millions of galaxies will form a fundamental scientific basis to identify and select candidates and / or false candidates for EM counterparts. LSST will observe in photometric bands covering the wavelength range from 0.3 to 1.1μm (u, g, r, i, z, y), with about 1000 visits in 10 years and pointing to the same celestial coordinates every 3 nights . It is estimated that to complete the mapping of the GW170817 event area, even in non-optimized conditions, the LSST telescope would have taken less than 20 sightings to reach r = 24.5 mag.

The discovery of the first coalescence event of two neutron stars (NS + NS), GW170817, inaugurated the study of kilonovae. To fully explore these phenomena it is necessary to increase the number of objects observed in order to understand the different behaviors and, ultimately, to provide more stringent clues on the Hubble constant value. When LSST goes into operation, GW’s detectors will be fully operational (the Japanese KAGRA detector is expected to be operational together with, possibly, the installation of LIGO in India), which will further reduce the area of ​​search for EM sources. Furthermore, the rate of NS + NS events will be higher, up to distances of a few hundred MPCs.